LXR linux/tools/testing/selftests/bpf/progs/connect_force

   1// SPDX-License-Identifier: GPL-2.0
   2#include <string.h>
   3
   4#include <linux/bpf.h>
   5#include <linux/in.h>
   6#include <linux/in6.h>
   7#include <sys/socket.h>
   8
   9#include <bpf/bpf_helpers.h>
  10#include <bpf/bpf_endian.h>
  11
  12#include <bpf_sockopt_helpers.h>
  13
  14char _license[] SEC("license") = "GPL";
  15
  16struct svc_addr {
  17        __be32 addr[4];
  18        __be16 port;
  19};
  20
  21struct {
  22        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  23        __uint(map_flags, BPF_F_NO_PREALLOC);
  24        __type(key, int);
  25        __type(value, struct svc_addr);
  26} service_mapping SEC(".maps");
  27
  28SEC("cgroup/connect6")
  29int connect6(struct bpf_sock_addr *ctx)
  30{
  31        struct sockaddr_in6 sa = {};
  32        struct svc_addr *orig;
  33
  34        /* Force local address to [::1]:22223. */
  35        sa.sin6_family = AF_INET6;
  36        sa.sin6_port = bpf_htons(22223);
  37        sa.sin6_addr.s6_addr32[3] = bpf_htonl(1);
  38
  39        if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
  40                return 0;
  41
  42        /* Rewire service [fc00::1]:60000 to backend [::1]:60124. */
  43        if (ctx->user_port == bpf_htons(60000)) {
  44                orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0,
  45                                          BPF_SK_STORAGE_GET_F_CREATE);
  46                if (!orig)
  47                        return 0;
  48
  49                orig->addr[0] = ctx->user_ip6[0];
  50                orig->addr[1] = ctx->user_ip6[1];
  51                orig->addr[2] = ctx->user_ip6[2];
  52                orig->addr[3] = ctx->user_ip6[3];
  53                orig->port = ctx->user_port;
  54
  55                ctx->user_ip6[0] = 0;
  56                ctx->user_ip6[1] = 0;
  57                ctx->user_ip6[2] = 0;
  58                ctx->user_ip6[3] = bpf_htonl(1);
  59                ctx->user_port = bpf_htons(60124);
  60        }
  61        return 1;
  62}
  63
  64SEC("cgroup/getsockname6")
  65int getsockname6(struct bpf_sock_addr *ctx)
  66{
  67        if (!get_set_sk_priority(ctx))
  68                return 1;
  69
  70        /* Expose local server as [fc00::1]:60000 to client. */
  71        if (ctx->user_port == bpf_htons(60124)) {
  72                ctx->user_ip6[0] = bpf_htonl(0xfc000000);
  73                ctx->user_ip6[1] = 0;
  74                ctx->user_ip6[2] = 0;
  75                ctx->user_ip6[3] = bpf_htonl(1);
  76                ctx->user_port = bpf_htons(60000);
  77        }
  78        return 1;
  79}
  80
  81SEC("cgroup/getpeername6")
  82int getpeername6(struct bpf_sock_addr *ctx)
  83{
  84        struct svc_addr *orig;
  85
  86        if (!get_set_sk_priority(ctx))
  87                return 1;
  88
  89        /* Expose service [fc00::1]:60000 as peer instead of backend. */
  90        if (ctx->user_port == bpf_htons(60124)) {
  91                orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0, 0);
  92                if (orig) {
  93                        ctx->user_ip6[0] = orig->addr[0];
  94                        ctx->user_ip6[1] = orig->addr[1];
  95                        ctx->user_ip6[2] = orig->addr[2];
  96                        ctx->user_ip6[3] = orig->addr[3];
  97                        ctx->user_port = orig->port;
  98                }
  99        }
 100        return 1;
 101}
 102